realprogrammers.com

DNS: Domain Name System/Service

DNS is an astonishingly complex subject, and this part of the site at
this stage only seeks to provide an overview of its operation. Even
after years of exposure even full-time sysadmins report feeling unease
with their mastery of DNS and how it works. Then spare a thought for
those who have only passing acquaintance with it!

The first article here has the target audience of those interested in
the most commonly seen aspects of DNS and how to debug basic DNS
problems. Later articles will explore the interaction of DNS and mail,
more advanced diagnoses, and administering the most common DNS servers.